The package - which was delivered by courier to a pharmacy on the same street as the market - was later destroyed in a controlled explosion. An employee opened the package, saw the device and called police, Herbst said.
According to reports, the suspicious package is reportedly 20 inches long and 16 inches wide and "has wires inside".
German police say a suspicious item found at a Christmas market in Potsdam has been confirmed to contain explosives.
The Reuters agency cited the Potsdamer Neueste Nachrichten newspaper, which said the package was around 40 cm by 50 cm and contained wires and electronics. The affected area in the inner-city of Potsdam has been evacuated.
Brandenburg state Interior Minister Karl-Heinz Schroeter told reporters the powder will be analyzed.
The German authorities have been on high security alert this week for the opening on the nation's Christmas markets 12 months after a Tunisian man ploughed a truck into a Berlin Christmas market, killing 12 people and injuring 56.
POLICE have evacuated a Christmas market in Germany after a bomb was delivered to nearby pharmacy, nearly a year after a deadly terrorist attack on a similar target.
Potsdam, a small but historic city, is the capital of Brandenburg state.
The German intelligence official, who spoke on condition of anonymity, further claimed the suspects had been carrying out target reconnaissance of the areas in which Christmas markets in Essen, Germany, would be held.